Evidence is required to establish "some basis in fact"
for the procedural preconditions to certification. This requires
certification judges tread the fine line between screening out
inappropriate class proceedings and impermissibly weighing of the
merits of the claim based on evidence at the certification stage.
The Alberta Court of Appeal's recent decision in Warner v. Smith & Nephew Inc.
(Justice Slatter dissenting) illustrates the continuing evolution
of the evidentiary threshold required for certification.
Competing Expert Reports on Causation
The plaintiff in Warner alleged a hip resurfacing
system caused toxic levels of metal ions in the blood and applied
for certification of a class action against the manufacturer. Each
party filed an expert report opining on, among other things,
causation of metal ions in the blood. The plaintiff's proposed
expert concluded that there was a "great deal of uncertainty
as to what the presence of serum metal ions actually means for the
The certification judge denied certification, finding that class
proceedings were not a preferable method for resolving the common
issue because there was very little prospect of the plaintiff
Court of Appeal Disagrees on Weight of Expert Evidence
On appeal the majority reversed the chambers decision and
certified the class action. In doing so, the majority held that the
certification judge improperly considered whether there was
"some basis in fact" for the claim itself, rather than
analyzing whether there was "some basis in fact" that a
class action was a preferable procedure.
In dissent, Justice Slatter reasoned that some minimal
evidentiary basis for the claim was required in order to show a
class proceeding was a preferable procedure. Based on the expert
evidence Justice Slatter found it "uncontradicted" that
no one knew the long term effects of metal ions in the blood. In
the face of an unresolved "scientific mystery", Justice
Slatter was of the view that the plaintiff failed to establish an
expert methodology that might demonstrate causation.
Warner underscores the continuing
uncertainty regarding the weight a certification court will give to
evidence in assessing whether the procedural requirements for
certification have been met. This issue has arisen frequently when
assessing the evidentiary threshold for the requirement of a
class-wide methodology to prove causation. For example, see our
posts on Miller v. Merck Frosst Canada Ltd. and Charlton v. Abbott Laboratories, Ltd. Going forward
courts will continue to tread the fine line between fulfilling
their gate-keeping function and impermissibly weighing the merits
at the certification stage.
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guide to the subject matter. Specialist advice should be sought
about your specific circumstances.
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